A Maryland inmate has been convicted of conspiring with two other men to fly drugs and other contraband into a maximum-security prison aboard a drone.

Charles Brooks was sentenced Thursday in Cumberland to 13 years after a jury convicted him on two conspiracy counts and two counts of possessing contraband.

Investigators testified at an earlier trial that Brooks was in a dog-training program that enabled him to walk his dog outside his housing unit alone at night and retrieve contraband.

Former inmates Thaddeus Shortz and Keith Russell were convicted earlier this year. They were arrested outside the Western Correctional Institution in August. Police found a drone and contraband materials in Shortz' truck.

Brooks is serving a life sentence for conspiracy to commit murder in Prince George's County in 2002.